UNCLASSIFIED
Table 1 - Average Concentrations of Strontium 90 in Stratospheric Samples Collected
November 1956 through January 1958
’
a/
(Strontium 90 content expressed in micromicrocuries per 1,000 cubic feet of air,
reduced to standard conditions.)
content
Number
of
Average
strontium 90
samples
10
5+ 5
14
10+ 7
8
15 + 10
n
65,000
ab + 15
17
29 + 12
10
50,000
9+ 5
19
2+ 2
10
3
%a
%
T+ 5
2
4
Number
of
content
eemples
5
9+ 9
12+ 8
uu
29 + 26
6
nD
-
0
17 + 13
~
y+
Ow
samples
Average
strontium 90
as
l+ 1
f
.
sof §:
ye
80,000
content
Number
of
Brazil
9
7+10d/
Ramples
Average
atrontium 90
Sao Paulo,
vegies
et
90,000
content
Number
of
———
a/Based on data available through June 26, 1958.
vf Range showa one standard deviation above and below average.
variations in strontium 90 content from month to month.
TIAA Jued
The
Analyses had not been completed on all samples collected during this period.
program calle for one sampie a month from each altitude at each location.
In some instances the semple was not recovered.
Standard deviations shown include both errors of measurement and
cf These samples were collected in the vicinity of the tropopause and probably do not represent stratospheric concentrations.
50,000-foot sampling level is usually below the stratosphere at this location
.
The
t
>
w
£ eat Ge Sia
(feet)
Average
atrontium 90
France Air Force Base
RT
iG
Altitude
Panama Canal Zone
San Angelo, Texas
i
Minneapolis, Minnesota
’
roe
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